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At least 19 recordsLinked to original sources

PubMed1990

Two-dimensional gel electrophoretic analyses of Kentucky bluegrass and rye grass pollen allergens. Detection with a murine monoclonal anti-Poa p I antibody and amino terminal amino acid sequence of Poa p I allergen.

Allergenic extracts of Kentucky bluegrass (Poa pratensis) and rye grass (Lolium perenne) pollen were shown by 2-dimensional (2-D) gel electrophoresis to consist of several hundred protein components. The pollen extracts of the two related grasses had unique 2-D gel patterns. Two major grass pollen allergens, Poa p I and Lol p I, and their isoforms (i.e. isoallergens) were detected and localized on 2-D gels by immunoblotting with anti-Poa p I antibody mAb 60. Poa p I isoallergens were less acidic than Lol p I isoallergens. The relative proportion of four Poa p I isoallergens was (in decreasing pI): A, 13%; B, 37%; and D, 15%. The amino terminal amino acid sequences of the two major isoallergens of Poa p I were identical. However, the amino acid composition of these isoallergens showed enough differences to account for their charge differences. The amino terminal amino acid sequence of two major Poa p I isoallergens had a 70% homology in 20 amino acid overlap with the previously published amino terminal amino acid sequence of rye grass pollen allergen R-7.

Allergens↗

PubMed2005

Genome relationships in polyploid Poa pratensis and other Poa species inferred from phylogenetic analysis of nuclear and chloroplast DNA sequences.

The genus Poa comprises approximately 500 species that occur throughout the world, including the widely grown Kentucky bluegrass (P. pratensis L.). Hybridization and polyploidization have played a prominent role in the evolution of this complex genus, but limited information is available regarding genome relationships in Poa. Thus, we amplified, cloned, and compared the DNA sequences of 2 nuclear genes (CDO504 and thioredoxin-like protein) and 2 chloroplast genome loci (ndhF and trnT-trnF) from 22 Poa species. Four distinct classes of sequences corresponding to 4 putative homoeologous loci from each nuclear gene were found within polyploid P. pratensis. Nuclear sequences from 15 other Poa species were found to group with at least 1 P. pratensis homoeolog, whereas 6 species displayed sequences not present in P. pratensis. The nuclear genome phylogenies presented here show the first evidence of diverse and related genomes in the genus Poa.

Cell Nucleus↗

PubMed1990

Mapping of epitopes on Poa p I and Lol p I allergens with monoclonal antibodies.

Allergen Poa p I isolated from the dialysed aqueous extract of Kentucky blue grass pollen by affinity chromatography with an anti-Lol p I murine monoclonal antibody (MAb) 290A-167 was previously shown to consist of a 35.8-kilodalton (kD) component with a pI of 6.4, designated as Poa p Ia, and a 33-kD component with a pI of 9.1, designated as Poa p Ib. The present study reports on the comparative antigenic analyses of these two components, using MAbs produced separately against Poa p I and Lol p I. Thus, anti-Poa p I MAbs 60 and 61 and anti-Lol p I MAb 290A-167 recognized Poa p Ia and Poa p Ib whereas anti-Poa p I MAbs 62, 63 and 64 and anti-Lol p I MAb 348A-6 recognized only Poa p Ia. The specificities of the MAbs were further resolved by comparing their respective abilities to inhibit the binding of 125I-Poa p I or 125I-Lol p I to the different MAbs prepared in the form of solid phase. These studies revealed that at least 4 distinct epitopes (designated as E1, E2, E3 and E4) were shared by both Poa p I and Lol p I. All 4 epitopes were present on Poa p Ia whereas only E1 and E3 were detected on Poa p Ib. E1 was recognized by MAbs 60 and 61, E2 by MAbs 62, 63 and 64, E3 by MAb 290A-167 and E4 by MAb 348A-6.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗

PubMedDate not supplied

Permanent effects of postnatal administration of beta-adrenergic ligands on the volume of sexually dimorphic nucleus of the preoptic area (SDN-POA) in rats.

BACKGROUND: beta-adrenergic ligands have been shown to influence sexual differentiation of the brain. In the present study we document that short postnatal treatment with beta-adrenergic agonists or antagonists may permanently reverse the morphological sex of the brain, as judged by the volume of sexually dimorphic nucleus of the preoptic area (SDN-POA). Female rats treated by beta(2)-adrenergic stimulating ligands exhibit an increased, male type SDN-POA volume while male rats treated by beta1-adrenergic antagonists show a decreased, female type of SDN-POA volume. OBJECTIVES: To analyze the volume of SDN-POA of adult rats after postnatal administration of betaadrenergic ligands. METHODS: From the second day of life, over 5 consecutive days, all the neonates were injected subcutaneously with the following drugs: isoproterenol, salbutamol, metoprolol alprenolol or saline. SDN-POA volumes were estimated planimetrically on serial brain slides. RESULTS: In male rats the mean volume of SDN-POA was 9.97 +/- 1.66 x 10(-3) mm(3), in female rats the respective volume reached 4.02 +/- 1.26 x 10(-3) mm(3) only and was 2.5 times lower, the difference being highly statistically significant. Postnatal administration of isoproterenol remained without effect in male rats but diminished the SDN-POA volume in female rats, thus increasing the sexual dimorphism. The disappearance of sexual dimorphism was noted in rats treated postnatally with salbutamol. This effect was due to the increase in SDN-POA volumes in female rats, up to 9.81 +/- 2.64 x 10(-3) mm(3), the levels approaching the male type of POA differentiation. Postnatal alprenolol treatment influenced the sexual dimorphism of the brain by decreasing the SDN-POA volume reached by adult males. In fact, in rats treated postnatally with alprenolol, the volume of the nucleus reached only 4,44 +/- 1,61 x 10(-3) mm(3), being not statistically different from female nuclei. The effect of metoprolol pretreatment was similar to alprenolol. Male volumes of SDN-POA were restored both by isoproterenol and salbutamol in metoprolol pretreated rats and by isoproterenol only in alprenolol treated rats. CONCLUSION: It appears that inhibition of beta(1)-adrenergic pathway is able to shut off the physiologic mechanisms of male differentiation of SDN-POA, and the subsequent beta(2)-adrenergic stimulation activates an alternative mechanism of masculinization. beta(2)-adrenergic signal is able to masculinize rat preoptic area in females as well. From the presented data it may be concluded that beta adrenoreceptors participate in sexual differentiation of preoptic area in rats and the modulation of their activity in postnatal period permanently influences the morphology of the sexually differentiated nucleus of the preoptic area.

Adrenergic beta-Agonists↗

PubMed1984

A pancreatic oncofetal antigen (POA): its characterization and application for enzyme immunoassay.

We investigated the usefulness of enzyme immunoassay (EIA) for pancreatic oncofetal antigen (POA). The crude POA isolated from POA-positive ascitic fluid of patients with pancreatic cancer was injected into rabbits to raise anti-POA serum. The adsorbed antiserum was used for EIA as anti-POA serum. For the establishment of EIA system for POA, anti-POA-Fab' fragment was conjugated to beta-D-galactosidase from Escherichia Coli. Normal subjects (205 controls) and 132 patients (47 with pancreatic cancer, 22 with chronic pancreatitis, and 63 with other malignant disease) were surveyed. The standard serum from patient M with pancreatic cancer was used in quantitatively determining serum POA levels; value was expressed arbitrarily as 1000U/ml. Normal upper limit of POA was defined as less than 400U/ml (mean + 2SD of normal subjects). POA level higher than normal was observed in 72% of patients with pancreatic cancer, 23-44% of patients with other malignant diseases, and 18% of patients with chronic pancreatitis. The susceptibility of the isolated POA to several enzymes and chemical reagents was also studied. These results suggest the usefulness of EIA for POA in diagnosis of pancreatic cancer.

Antigens, Neoplasm↗

PubMed1988

Isolation and characterization of Poa p I allergens of Kentucky bluegrass pollen with a murine monoclonal anti-Lol p I antibody.

The Poa p I allergens were isolated from the retentate fraction of a dialyzed preparation of an aqueous extract of Kentucky bluegrass pollen by means of a reverse immunosorbent prepared with a murine anti-Lol p I monoclonal antibody, Mab 290-A-167. By sodium dodecyl sulphate-polyacrylamide gel electrophoresis and preparative isoelectrofocusing, Poa p I was found to consist of a 35.8-kD component with an isoelectric point of 6.4 and a 33-kD component with one of 9.1 and designated as Poa p Ia (acidic) and Poa p Ib (basic), respectively. The relative protein content of these components was estimated from the intensity of the stained bands following sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Thus, Poa p Ia appeared to be the major protein constituent, and on Western immunoblot it also bound the monoclonal antibody to a greater extent than Poa p Ib. On the other hand, Poa p Ib was shown by Western immunoblot and autoradiographic analysis, to bind to a greater extent the IgE antibodies present in a pool of sera from grass-allergic individuals. Therefore, Poa p Ib was considered as the major allergenic component of Poa p I. By competitive inhibition of the radioallergosorbent test, it was demonstrated that the Mab inhibited the binding of Poa p I allergens to human IgE antibodies to the extent of 70%. Hence, it is suggested that Mab and human IgE antibodies recognize identical or closely related determinants of Poa p I allergens.

Allergens↗

PubMed1997

Leaf Respiration in Light and Darkness (A Comparison of Slow- and Fast-Growing Poa Species).

We investigated whether leaf dark respiration (nonphotorespiratory mitochondrial CO2 release) is inhibited by light in several Poa species, and whether differences in light inhibition between the species are related to differences in the rate of leaf net photosynthesis. Four lowland (Poa annua L., Poa compressa L., Poa pratensis L., and Poa trivialis L.), one subalpine (Poa alpina L.), and two alpine (Poa costiniana Vick. and Poa fawcettiae Vick.) Poa species differing in whole plant relative growth rates were grown under identical controlled conditions. Nonphotorespiratory mitochondrial CO2 release in the light (Rd) was estimated according to the Laisk method. Photosynthesis was measured at ambient CO2 partial pressure (35 Pa) and 500 [mu]mol photons m-2 s-1. The rate of photosynthesis per unit leaf mass was positively correlated with the relative growth rate, with the slow-growing alpine Poa species exhibiting the lowest photosynthetic rates. Rates of both Rd and respiration in darkness were also substantially lower in the alpine species. Nonphotorespiratory CO2 release in darkness was higher than Rd in all species. However, despite some variation between the species in the level of light inhibition of respiration, no relationship was observed between the level of inhibition and the rate of photosynthesis. Similarly, the level of inhibition was not correlated with the relative growth rate. Our results support the suggestion that rates of leaf respiration in the light are closely associated with rates in darkness.

Journal Article↗

PubMed1986

[Studies on a pancreatic oncofetal antigen (POA) in patients with pancreatic cancer].

An enzyme immunoassay for POA prepared by Gelder et al. was developed in our laboratory. Elevated serum POA levels were shown in 70.6% (36/51) of patients with pancreatic cancer. POA levels were related neither to the stage nor to the degree of differentiation of pancreatic cancer. Although POA levels were not elevated in patients with benign diseases of the pancreas, they were elevated in patients with cancer of the hepato-biliary tract. In pancreatic cancer patients with pre-operative high POA levels, serial POA determinations following tumor resection are considered to be useful for detecting recurrence of disease. Employing the unlabeled antibody peroxidase-antiperoxidase (PAP) method, POA was detected in the cytoplasm of cancer cells in 80.0% (28/35) of pancreatic cancer patients, but not in histologically normal pancreatic tissue. Well differentiated cancer cells showed higher POA stainability than less differentiated ones. POA was also detected in fetal pancreas tissues of 22 weeks gestation, but not in those of 12-16 weeks gestation. This result suggests that POA is an oncofetal antigen.

Adult↗

PubMed1988

Cytoarchitectonic analysis of the SDN-POA of the intact and gonadectomized rat.

The densely staining group of cells referred to as the sexually dimorphic nucleus of the preoptic area (SDN-POA) is greater in volume in the male than in the female rat. Because we and others have reported absolute volumes that have been consistent within individual studies but that vary considerably, we characterized the SDN-POA by describing its morphology with respect to the cytoarchitectonic divisions of the medial preoptic nucleus (MPN) in intact and gonadectomized rats. We report three major findings: the SDN-POA is heterogeneous and is composed of cells belonging to three distinct cytoarchitectonic divisions; the cytoarchitecture of the MPN and its medial and lateral divisions (MPNm and MPNl, respectively) in male rats appear to be influenced by the hormonal status in adulthood; and a small anteroventral division of the MPN (MPNav) is present in males but virtually absent in females. Specifically, the SDN-POA is located within the MPNm, but consists of subcomponents located within the central division of the MPN (MPNc), the MPNav, and part of the MPNm-exclusive of the MPNc and MPNav. The percentage of the total SDN-POA located within the MPNc and MPNav. The percentage of the total SDN-POA located within the MPNc and MPNav was greater in males, and that in the MPNm-exclusive of the MPNc and MPNav was greater in females, indicating that the SDN-POA has a different cytoarchitectonic composition in the two sexes. Gonadectomy produced no significant differences in SDN-POA volume, but the MPN, MPNl, and MPNm were significantly reduced in gonadectomized versus intact males, suggesting an activational effect of testicular hormones on these structures.

Animals↗

PubMed1983

[Pancreatic oncofetal antigen (POA)--its characterization and the result of enzyme immunoassay].

Our studies on the partial purification, characterization and clinical application of pancreatic oncofetal antigen (POA) are presented. This antigen was purified from fetal pancreas and migrated in beta-region electrophoretically. Its molecular weight was estimated approximately 80 X 10(4) daltons on gel filtration. POA prepared by us was different from either Nishida's POA biochemically or Shimano's PCAA immunologically. Enzyme immunoassay of POA was established by conjugating with anti-POA with-D-galactosidase. Among 60 patients with carcinoma of the pancreas, 44 (73.3%) had a elevated serum POA level. A serological screening of pancreatic cancer was performed among 440 out-patients with combined assay of tumor markers including POA. Five cases with carcinoma of the pancreas were found out by this screening test. These findings indicate that serum POA assay is clinically useful.

Adult↗

PubMed1991

Identification and characterization of the Poa p IX group of basic allergens of Kentucky bluegrass pollen.

We reported previously the primary structure of three full-length cDNA clones that encode a new group of IgE-binding proteins of Kentucky bluegrass (KBG) pollen, designated as Poa p IX. In the present study we have further characterized the cloned Poa p IX proteins, identified the corresponding proteins in KBG pollen extract, and determined their antigenic relationships with other known grass pollen allergens. A recombinant IgE-binding polypeptide rKBG7.2 that represents the C-terminal fragment, conserved in Poa p IX proteins, appeared to contain epitopes unique to these proteins and served as an immunosorbent for the isolation of the corresponding human IgE antibodies. On two-dimensional PAGE blots these IgE antibodies bound selectively to five distinct KBG pollen proteins with molecular mass 28 to 34 kDa and isoelectric point greater than 9.5. These proteins differ in size and charge from known allergens, but are very similar to those of the recombinant Poa p IX proteins. The rKBG3.1, which represents the N-terminal region of the Poa p IX clone KBG31, as well as the corresponding natural allergens were shown to possess epitopes that crossreact with the acidic group V allergens of Timothy. Comparison of amino acid sequences of recombinant Poa p IX proteins with those of Lol p I isoallergens revealed no significant sequence similarities. In contrast, partial homology was demonstrated between the N-terminal sequences of these proteins and the Phl p V proteins. Our results confirm that the Poa p IX clones represent a distinct and major group of allergens of KBG pollen, and demonstrate structural similarities and antigenic cross-reactivities among different groups of allergenic proteins in grass pollens.

Allergens↗

PubMed1984

[Pancreatic oncofetal antigen (POA) and carcinoma of the pancreas].

Pancreatic oncofetal antigen (POA) was purified from fetal pancreas and migrated in beta-region electrophoretically. Its molecular weight was 80 X 10(4) daltons. Enzyme immunoassay for serum POA revealed that elevated levels of POA were found in sera of patients with pancreatic cancer. By a serological screening of 440 out-patients with combined assay of tumor markers including POA, 4 cases of pancreatic cancer were found. POA was demonstrated in the ductal cells of fetal pancreas and cancer cells of duct cell type pancreatic adenocarcinoma immunohistochemically. Elevated levels of serum POA of patients with pancreatic cancer was probably derived from cancer tissue. These findings indicate that serum POA assay is clinically useful.

Adenocarcinoma↗

PubMed1983

[Evaluation of pancreatic oncofetal antigen (POA) in the diagnosis of pancreatic cancer].

Pancreatic oncofetal antigen (POA) is considered to be an oncofetal antigen for human pancreas, and its measurement seems to be useful in the diagnosis of pancreatic cancer. In this study, POA, CEA, ferritin, BMG (beta 2 microglobulin) and AFP either in sera in pancreatic juice were measured in patients with pancreatic cancer, chronic pancreatitis and other various diseases, and their diagnostic value was comparatively evaluated. POA showed the highest sensitivity for pancreatic cancer compared with CEA or others. POA and CEA in pancreatic juice showed higher sensitivity and specificity than those in serum, probably reflecting the earlier malignant status. Localization of POA was immunohistochemically observed in tissues of pancreatic cancer and fetal pancreas. In some cases of pancreatic cancer with elevated serum CEA, ferritin and BMG, only CEA was positive in cancer cells, indicating that CEA is produced from cancer cells while ferritin and BMG are not produced from them. The combined assay of POA and CEA improved sensitivity for the diagnosis of pancreatic cancer. It is concluded that POA could be a useful tumor marker providing valuable information in the clinical diagnostic system of pancreatic cancer.

Antigens, Neoplasm↗

PubMed1978

Studies on an oncofetal antigen, POA.

This paper describes the purification and partial characteristics of a putative oncofetal antigen, POA, which appears to be associated with the pancreas. POA is a glycoprotein of molecular weight between 800,000 and 900,000 daltons. It is found in fetal pancreas and pancreas cancer tissue, but not in normal adult pancreas. It is clearly different from carcinoembryonic antigen, other known tumor associated antigens, acute phase reactants and normal serum proteins. A quantitative rocket immunoelectrophoresis assay was developed for POA. Its specificity was monitored routinely by double immunodiffusion against known fetal and adult standards. The assay was performed on sera from over 700 patients. The results demonstrate that POA is found in the sera of most individuals. However, by far the highest absolute levels and the highest frequency of elevated levels was found in sera of patients with carcinoma of the pancreas. Elevated levels of POA were also found in the serum of a proportion of patients with carcinomas of the lung, stomach, colon, biliary tract, and breast and in a few other individuals with benign conditions. The spectrum of patients who have elevated levels of POA in their serum is quite different from that found with CEA or other known tumor markers.

Antigens, Neoplasm↗

PubMed2002

Ethylene emission and responsiveness to applied ethylene vary among Poa species that inherently differ in leaf elongation rates.

A plant's ability to produce and respond to ethylene is essential for its vegetative growth. We studied whole-shoot ethylene emission and leaf growth responses to applied ethylene in four Poa spp. that differ inherently in leaf elongation rate and whole-plant relative growth rate. Compared with the fast-growing Poa annua and Poa trivialis, the shoots of the slow-growing species Poa alpina and Poa compressa emitted daily 30% to 50% less ethylene, and their leaf elongation rate was more strongly inhibited when ethylene concentration was increased up to 1 microL L(-1). To our surprise, however, low ethylene concentrations (0.02-0.03 microL L(-1)) promoted leaf growth in the two slow-growing species; at the same concentrations, leaf elongation rate of the two fast-growing species was only slightly inhibited. All responses were observed within 20 min after ethylene applications. Although ethylene generally inhibits growth, our results show that in some species, it may actually stimulate growth. Moreover, in the two slow-growing Poa spp., both growth stimulation and inhibition occurred in a narrow ethylene concentration range, and this effect was associated with a much lower ethylene emission. These findings suggest that the regulation of ethylene production rates and perception of the gas may be more crucial during leaf expansion of these species under non-stressful conditions and that endogenous ethylene concentrations are not large enough to saturate leaf growth responses. In the two fast-growing species, a comparatively higher ethylene endogenous concentration may conversely be present and sufficiently high to saturate leaf elongation responses, invariably leading to growth inhibition.

Dose-Response Relationship, Drug↗

PubMed1985

Evidence that prostaglandins within preoptic area (POA) may mediate the antidipsogenic effect of Escherichia coli endotoxin in the rat.

Intravenous injection of Escherichia coli endotoxin (LPS; 640 micrograms/kg) produced an antidipsogenic effect in 48-h water-deprived rats, which was antagonized by acetylsalicylic acid (ASA; 0.45, 0.9 microM) injected directly into cerebral preoptic area (POA). ASA (0.9 microM) when injected into POA did not elicit, by itself, any effect on drinking. Endotoxin (0.5, 1, and 2 micrograms), when injected directly into POA, produced a dose-dependent inhibition of drinking stimulated by water deprivation. This effect was antagonized by ASA (0.45 microM) injected into POA 15 min before LPS. Injection of LPS (2 micrograms) into brain areas not involved in drinking regulation (superior colliculus or nucleus caudatus) was without effect on 48-h water deprivation-induced thirst. PGI2 (5, 50, and 500 ng) injected ino POA showed a dose-dependent antidipsogenic effect on drinking stimulated by water deprivation. The data suggest that prostaglandins, within the preoptic area, might be involved in the antidipsogenic effect of E coli LPS, given either intravenously or directly into POA.

Animals↗

PubMed1994

Androgen enhances neuronal degeneration in the developing preoptic area: apoptosis in the anteroventral periventricular nucleus (AVPvN-POA).

Perinatal treatment of female rats with androgen decreases the nuclear volume of the anteroventral periventricular nucleus of the preoptic area (AVPvN-POA). In order to examine the effect of androgen on neurogenesis, bromodeoxyuridine (BrdU) was given once on Day 15 of gestation (= E15) to pregnant rats that also received testosterone propionate (TP) injections. When examined at E17, the number of BrdU-labeled neurons in the AVPvN-POA was not significantly different among control female, male, and androgenized female fetuses, suggesting that androgen does not interfere with neurogenesis. At E21, a significant reduction of BrdU-labeled AVPvN neurons was observed in males and androgenized females. These findings support the hypothesis that elimination of a population by cell death is enhanced in males and androgenized females. Similar selective elimination of the AVPvN neurons occurred in the female following neonatal TP treatment. In order to investigate the nature of androgen-induced cell death in the AVPvN-POA, specific labeling of nuclear DNA fragmentation was performed by the TdT-mediated dUTP-biotin nick end-labeling (TUNEL) method. The number of TUNEL-positive cells was significantly greater in neonatally androgenized females, compared to that in control females. Since DNA fragmentation is considered the most characteristic feature of apoptosis, and TUNEL method is based on direct, specific labeling of DNA fragmentation in nuclei in situ, the neuronal death in the AVPvN-POA is apoptotic, and perinatal androgen may induce the selective apoptotic cell death in the AVPvN-POA.

Animals↗

PubMed1985

Effects of prenatal stress on differentiation of the sexually dimorphic nucleus of the preoptic area (SDN-POA) of the rat brain.

The present study was designed to determine the effects of prenatal malnutrition or environmental stress on the development of the sexually dimorphic nucleus of the preoptic area (SDN-POA). Pregnant rats were divided into a control group and two treatment groups (immobilization-illumination-heat or environmental stress, and nutritional stress). The two forms of stress were administered during the third trimester of gestation (days 14-20). Male and female offspring were sacrificed at birth, 20, and 60 days postnatally. The cross-sectional area of the SDN-POA was identified under light microscopy and was measured. The data confirm previous studies by showing a significant sex difference in the SDN-POA between control male and female rats. Prenatally stressed males sacrificed 20 and 60 days after birth showed SDN-POA areas 50% smaller than the nuclear areas of control males. The size of the SDN-POA of female offspring, however, was not significantly altered by prenatal treatments.

Animals↗